Walnut tree named &#39;Solano&#39;

ABSTRACT

A new and distinct cultivar of walnut tree denominated ‘Solano’ is described. This new cultivar, ‘Solano’, comes into bearing young, with an excellent yield. ‘Solano’ forms jumbo-sized walnuts that possess light-colored kernels with little size variation in a given harvest. ‘Solano’ bears fruit terminally and laterally and yields a crop that can be harvested approximately 2 weeks before ‘Chandler’ (U.S. Plant Pat. No. 4,388). ‘Solano’ is also protandrous, bearing male flowers before female flowers.

LATIN NAME

Botanical/commercial classification: (Juglans regia), new English walnut tree cultivar.

VARIETAL DENOMINATION

The varietal denomination of the claimed walnut is ‘Solano’.

BACKGROUND OF INVENTION

The present invention relates to a new and distinct cultivar of walnut tree (Juglans regia) that has been denominated as ‘Solano’ and more particularly to a walnut tree that has a harvest date approximately 2 weeks earlier than the walnut tree cultivar ‘Chandler’ (U.S. Plant Pat. No. 4,388), and that further produces a walnut that is jumbo in size with light colored kernels.

It has long been recognized as desirable to provide walnut trees bearing large crops that are ripe for commercial harvesting and shipment early in the harvest season. The tree of the present cultivar, ‘Solano’, produces a nut that has a quality similar to the highest quality cultivar ‘Chandler’ (U.S. Plant Pat. No. 4,388). However, the new cultivar is ready for harvest approximately 2 weeks before ‘Chandler’, which is about the same time as the reference cultivar ‘Vina’ (old cultivar; not patented).

The new Juglans regia walnut tree of the present invention was created at Davis, Calif. in Year 1 by a controlled pollination between the cultivar ‘Chico’ and ‘UC67-13’ (neither patented). The pedigree is illustrated (FIG. 1).

Seeds from the cross were planted and the resulting 29 trees were carefully observed along with other trees in the walnut breeding program. When the trees began to bear nuts, data were collected annually on leafing date, first, peak and last female flower bloom, first, peak and last male bloom, blight severity, and yield (Table 1). Nuts were sampled, cracked, and data was collected on shell appearance, shell thickness, shell integrity, shell strength, nut weight, kernel weight, percent kernel, ease of kernel removal, kernel color, and percent kernel shrivel (Table 1). A single tree was selected from among progeny of this controlled cross based on its superior attributes. This selection was originally designated ‘UC95-11-16’ and is now designated as the ‘Solano’ cultivar after the county in California. Compared to ‘Solano’, the parent ‘UC67-13’ has larger nuts, an earlier harvesting date, and is susceptible to pistillate flower abscission. The parent ‘Chico’ is protogynous and has smaller nuts than ‘Solano’ with a more difficult to extract kernel (Table 1).

The new ‘Solano’ cultivar of the present invention has been asexually reproduced by grafting at Davis, Calif. and in various field trials on ‘Paradox’ rootstock. The distinctive characteristics of the new cultivar have been found to be stable and are transmitted to the new trees when asexually propagated.

SUMMARY OF THE INVENTION

It was found that the walnut cultivar ‘Solano’ of the present invention exhibits the following combination of characteristics:

-   -   a) comes into bearing young, with an excellent yield;     -   b) forms jumbo-sized walnuts that possess light-colored kernels         with little size variation in a given harvest;     -   c) bears fruit terminally and laterally;     -   d) yields a crop that can be harvested approximately 2 weeks         before ‘Chandler’ (U.S. Plant Pat. No. 4,388); and     -   e) is protandrous, bearing male flowers before female flowers.

BRIEF DESCRIPTION OF THE TABLE

Table 1 shows tree and nut evaluations for both parents and the most common walnut cultivar ‘Chandler’.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows pedigree of the ‘Solano’ walnut tree.

FIG. 2 shows a ‘Solano’ walnut tree at 8 years old.

FIG. 3 shows bark of a ‘Solano’ walnut tree.

FIG. 4 shows an adaxial view of a typical leaf of a ‘Solano’ walnut tree.

FIG. 5 shows an abaxial view of a typical leaf of a ‘Solano’ walnut tree.

FIG. 6 shows female flowers of a ‘Solano’ walnut tree.

FIG. 7 shows catkins (male flowers) of a ‘Solano’ walnut tree.

FIG. 8 shows hulls from a ‘Solano’ walnut tree before opening and exposing the nuts.

FIG. 9 shows nuts from a ‘Solano’ walnut tree.

FIG. 10 shows kernels from a ‘Solano’ walnut tree.

BOTANICAL DESCRIPTION OF THE PLANT

The following description is based on an ungrafted walnut tree on its own roots and trees subsequently grafted on ‘Paradox’ rootstock in selection blocks at Davis, Calif., Chico, Calif., and Parlier, Calif.; as well as in grower trials near Madison, Calif., near Durham, Calif., and near Wheatland, Calif. The first data were collected on the own rooted tree from Year 4 at age 3 years, to Year 11, age 10. Data from Year 9 to Year 15 were collected from grafted trees.

The Munsell Book of Color was used in the identification of color. Also, common color terms are to be accorded their ordinary dictionary significance.

-   Botanical classification: Juglans regia.     -   -   Female parent.—‘UC67-13’.         -   Male parent.—‘Chico’. The pedigree is shown in FIG. 1. -   Plant: The growth habit of the plant is illustrated in FIG. 2. This     8 year old tree is approximately 7.2 meters in height with a canopy     diameter of 8.1 meters. The trunk diameter at 0.5 meters above the     ground is approximately 24 cm. The silvery grey bark is typical of     Juglans regia. The young bark is brown (5Y 5/2) and the older bark     is grey (5Y 7.5/2) with raised lighter lenticels (2.5Y 8/2) (FIG.     3). Lenticels are round to oval in shape, 1-10 mm×1-3 mm in size.     ‘Solano’ has vigor similar to ‘Chandler’. -   Foliage: The dark green foliage is illustrated in FIG. 4 and FIG. 5,     and is typical of Juglans regia. Leafing out date between Year 4 and     Year 15 has occurred on March 25^(th) on the average. For     comparative purposes the ‘Chandler’ cultivar leaf-out is April     4^(th). The typical leaf coloration is green (adaxial 5GY 3/4,     abaxial 5GY 5/4). The leaves are pinnately compound with 7-9     leaflets. The full leaf length is approximately 38 cm and the width     is 30 cm. Leaflets are broadly elliptical and entire. The terminal     leaflet averages 17 cm in length and 9 cm in width. The middle     leaflets average 15 cm in length and 6 cm in width, and the proximal     leaflets average 6 cm in length and 3.5 cm in width. The rachis     averages 22 cm in length and 2-4 mm in diameter. Petiole length is 7     cm and is 2.5GY 7/6 in color. -   Inflorescence: The tree is precocious with excellent yield being     noted at age 3 years. Male flowers (catkins) were first present at     age 4 years. This delay in male maturity is typical of Juglans     regia. From Year 4 to Year 15, average first female bloom occurred     on April 9^(th), peak bloom on April 13^(th) and last bloom on April     19^(th). From Year 5 to Year 15, average male flowering (pollen     shedding) began March 28^(th), peaked on April 2^(nd), and     terminated on April 11^(th). Pollen shedding in this protandrous     cultivar does not completely cover pistillate bloom, suggesting that     a pollenizer would be needed for maximum yield in isolated areas.     ‘Chandler’ (U.S. Plant Pat. No. 4,388), ‘Howard’ (U.S. Plant Pat.     No. 4,405), and ‘Tulare’ (U.S. Plant Pat. No. 8,268), would all be     satisfactory pollenizers. The female flowers are typical of Juglans     regia (FIG. 6), with 2-3 flowers per inflorescence borne on 1 cm     spike at both terminal and lateral positions on current season's     growth. Approximately 100% of the lateral buds contain     inflorescences making yields much greater than trees that only bear     flowers terminally. A typical female flower is approximately 5 to 7     mm at anthesis and floral organs are typical of Juglans regia. The     flowers appear vase-shaped when the 2 plumose stigmatic arms are     curved outward. There are no petals. The female flowers are green in     color (5GY 7/8). The flower fragrance is typical of Juglans regia     and is not noticeably different than the foliage fragrance. The male     flowers (FIG. 7) are borne on catkins, between 7.5 and 14 cm in     length and 1.5 cm in diameter, and are green in color (5GY 7/8). -   Walnuts: The new cultivar ‘Solano’ commonly harvests about 2 weeks     before ‘Chandler’, about one week after ‘Payne’, and is similar in     timing to ‘Vina’. The new cultivar has excellent yields of mostly     jumbo-sized walnuts. The hull is globose, 5.5 cm×5.0 cm, 6 mm thick,     and 2.5GY 6/6 in color with numerous lighter speckles (FIG. 8). The     nut is broadly elliptical, has a slightly rough but uniform and     attractive appearance, is tan in color (7.5YR 6/4), and measures     approximately 42 mm in length and 36 mm in width (FIG. 9). The shell     is 1.3 mm thick, relatively strong and well-sealed, suitable for     in-shell marketing, and the kernel is easy to remove. The kernel     weight averages 8.0 g and makes up 55% of the total nut weight of     14.6 g. Kernel color is considered excellent (FIG. 10), and scores     mostly in the light to extra light categories of the USDA Standards     for Grades of Shelled Walnuts as determined by using the standard     Walnut Color Chart for kernels published by the Dried Fruit     Association of California. In addition, kernels of ‘Solano’ have     averaged 54.8 on the Relative Light Index used by Diamond Foods of     Stockton, Calif. Walnuts of the new cultivar ‘Solano’ are typical of     commercial walnuts in terms of flavor and firmness, the latter     varying according to the percent moisture after drying. -   Disease susceptibility: The response of the new cultivar ‘Solano’ to     Xanthomonas campestris pv. juglandis and walnut husk fly (Rhagoletis     completa) appears to be typical of mid-season cultivars. -   Usage: The new cultivar ‘Solano’ of the present invention provides a     relatively early to mid-season walnut with high quality     light-colored kernels that can be used cracked or in-shell.

TABLE 1 Performance of ‘Solano’ compared to ‘UC67-13’, ‘Chico’, ‘Chandler’, and ‘Vina’. Variety Trait¹ Solano² UC67-13³ Leafing 3/25 (1.83)  22⁴ 3/24 (1.08) 19 date Pollen First 3/28 (2.03) 13 3/31 (1.74) 17 shed Peak 4/2  (1.98) 13 4/6  (1.52) 17 date Last 4/11 (1.82) 13 4/19 (1.33) 16 Female First 4/9  (1.58) 18 4/6  (1.31) 17 bloom Peak 4/13 (1.50) 18 4/12 (1.15) 16 date Last 4/19 (1.67) 18 4/19 (1.14) 16 Harvest 9/24 (1.20) 36 9/21 (1.64) 17 date Days 7 (1.05) 19 6 (1.43) 11 after Payne leafing Days −9 (0.91) 19 −12 (1.19) 11 after Chandler leafing Catkin 5.2 (0.61) 14 6.3 (0.49) 18 abun- dance Female 6.3 (0.22) 16 5.8 (0.35) 11 abun- dance Flowers/ 2.0 (0) 17 2.0 (0) 16 inflores- cence Percent 95.3 (2.29) 17 96.6 (1.18) 16 lateral bud fruit- fulness Yield 6.4 (0.18) 32 5.6 (0.31) 17 Shell Texture 4.9 (0.07) 35 5.0 (0.67) 10 Color 4.7 (0.10) 35 4.8 (0.42) 10 Seal 5.1 (0.06) 35 5.0 (0) 11 Strength 5.0 (0.06) 35 5.1 (0.30) 11 Integrity 7.0 (0) 35 7.0 (0)  5 Thick- 1.3 (0.02) 35 1.5 (0.13) 11 ness Packing 5.0 (0) 35 5.1 (0.57) 10 tissue Kernel Inshell 14.6 (0.24) 35 15.3 (1.78) 11 weight Kernel 8.0 (0.16) 35 8.5 (1.55) 11 weight Percent 54.6 (0.45) 35 55.4 (2.16) 11 kernel Fill 5.4 (0.09) 35 4.7 (1.27) 11 Plump- 5.4 (0.08) 35 4.7 (1.10) 11 ness Ease of 4.7 (0.07) 35 4.3 (0.48) 10 removal Percent 0.6 (0.40) 35 2.7 (6.47)  4 blank Percent 33.8 (5.48) 35 18.8 (35.7) 11 extra light Percent 57.4 (4.92) 35 72.6 (33.7) 11 light Percent 9.8 (2.34) 35 6.7 (4.05) 11 light amber Percent 0 0 35 1.8 (6.03) 11 amber Percent 11.8 (3.2) 35 1.1 (3.51) 10 tip shrivel Percent 16.6 (3.12) 35 44.4 (22.4) 11 veins Variety Trait¹ Chico³ Chandler² Leafing 3/22 (1.13) 27 4/4  (0.72) 80 date Pollen First 4/7  (1.30) 23 4/6  (0.83) 75 shed Peak 4/13 (1.16) 24 4/14 (0.72) 74 date Last 4/20 (1.01) 23 4/21 (0.81) 73 Female First 3/25 (0.92) 25 4/17 (0.72) 77 bloom Peak 4/1  (1.02) 25 4/23 (0.68) 77 date Last 4/9  (1.15) 25 4/30 (0.71) 76 Harvest 9/18 (1.76) 24 10/8 (0.72) 91 date Days 3 (0.45) 18 17 (0.60) 64 after Payne leafing Days −15 (0.97) 18 0 (0.34) 64 after Chandler leafing Catkin 5.3 (0.28) 23 4.9 (0.20) 75 abun- dance Female 6.1 (0.26) 22 6.1 (0.13) 67 abun- dance Flowers/ 2.0 (0) 25 2.0 (0.01) 70 inflores- cence Percent 99.9 (0.08) 25 95.7 (0.75) 68 lateral bud fruit- fulness Yield 6.3 (0.26) 27 5.7 (0.12) 92 Shell Texture 4.2 (0.15) 17 4.7 (0.05) 87 Color 4.6 (0.15) 17 4.3 (0.06) 87 Seal 5.4 (0.15) 18 4.9 (0.03) 88 Strength 5.7 (0.11) 18 4.5 (0.07) 88 Integrity 7.1 (0.10) 14 7 .0 (0) 82 Thick- 1.5 (0.03) 18 1.3 (0.02) 88 ness Packing 5.6 (0.12) 17 4.7 (0.05) 86 tissue Kernel Inshell 11.4 (0.29) 18 13.4 (0.19) 88 weight Kernel 5.3 (0.12) 18 6.6 (0.10) 88 weight Percent 47.1 (0.57) 18 49.5 (0.27) 88 kernel Fill 5.7 (0.47) 13 4.5 (0.06) 88 Plump- 4.5 (0.20) 18 4.3 (0.06) 87 ness Ease of 6.5 (0.17 17 3.9 (0.05) 87 removal Percent 2.4 (1.06) 17 1.3 (0.36) 87 blank Percent 9.4 (5.60) 17 50.8 (4.22) 86 extra light Percent 76.0 (7.41) 17 44.2 (3.82) 86 light Percent 12.0 (4.81) 17 4.6 (1.32) 86 light amber Percent 2.6 (2.03) 17 0.4 (0.21) 86 amber Percent 0 (0) 17 30.5 (2.60) 86 tip shrivel Percent 19.2 (5.48) 17 18.3 (2.78) 85 veins Variety Trait¹ Vina³ Leafing 3/26 (0.89) 41 date Pollen First 3/28 (0.99) 39 shed Peak 4/5  (1.01) 39 date Last 4/14 (1.04) 39 Female First 4/8  (1.05) 40 bloom Peak 4/13 (0.87) 40 date Last 4/21 (0.93) 40 Harvest 9/23 (1.06) 49 date Days 8 (0.47) 39 after Payne leafing Days −9 (0.62) 39 after Chandler leafing Catkin 5.7 (0.21) 39 abun- dance Female 6.6 (0.16) 35 abun- dance Flowers/ 2.0 (0) 37 inflores- cence Percent 93.4 (1.92) 34 lateral bud fruit- fulness Yield 6.5 (0.14) 51 Shell Texture 5.0 (0) 49 Color 5.2 (0.07) 49 Seal 5.2 (0.05) 50 Strength 5.1 (0.04) 50 Integrity 7.0 (0) 46 Thick- 1.4 (0.02) 50 ness Packing 5 (0.03) 49 tissue Kernel Inshell 12.8 (0.24) 50 weight Kernel 3.3 (0.13) 50 weight Percent 49.3 (0.30) 50 kernel Fill 5.1 (0.08) 50 Plump- 4.8 (0.08) 50 ness Ease of 4.9 (0.11) 50 removal Percent 2.0 (0.58) 49 blank Percent 4.1 (2.90) 49 extra light Percent 48.1 (4.99) 49 light Percent 45.1 (4.86) 49 light amber Percent 2.5 (1.33) 49 amber Percent 2.3 (0.91) 49 tip shrivel Percent 30.4 (5.04) 49 veins ¹See attached key for description of scores; ²Data Year 4 to Year 15; ³Data Year Minus 6 to Year 15; ⁴Data mean, (Std. Error), n

In Table 1 the data for ‘Solano’ was collected over 11 years, from Year 4 to Year 15. The data for ‘UC67-13’, ‘Chico’, ‘Chandler’, and ‘Vina’ was collected over the course of 21 years, from Year Minus 6 to Year 15. In Table 1, in the row “Days after Chandler leafing” negative numbers refer to days before ‘Chandler’ leafing. Additionally, in footnote 4 of Table 1, “n” refers to the number of observations. Accordingly, the data in Table 1 are listed as mean values of the number of observations, including the standard error (Std. Error) in parentheses.

KEY FOR TABLE 1

Tree Evaluation

Catkin abundance Male flower abundance: 3 low; 5 intermediate; 7 high

Female abundance Female flower abundance: 3 low; 5 intermediate; 7 high

Lateral fruitfulness % Percent of lateral buds with female flowers

Yield Yield: 3 low; 5 intermediate; 7 high

Nut and Kernel Traits

Texture Shell texture: 3, smooth; 5 medium; 7 rough

Color Shell color: 3 light; 5 medium; 7 dark

Seal Shell seal: 3 weak; 5 intermediate; 7 strong

Strength Shell strength: 3 weak; 5 intermediate; 7 strong

Integrity Shell integrity: 3 substantial areas of shell missing;

-   -   5 small areas of shell missing; 6 hole in stem end; 7 complete         shell

Thickness Shell thickness at mid-cheek in mm

Packing tissue Inner lining: 3 thin; 5 medium; 7 thick

Inshell weight g

Kernel weight g

Kernel % Kernel wt/inshell wt×100

Fill Kernel fill: 3 poor; 5 moderate; 7 well

Plumpness Kernel plumpness: 3 thin; 5 moderate; 7 plump

Ease of removal Ease of removal of kernel halves: 3 easy; 5 moderate; 7 difficult

Blanks % Percent of nuts without a kernel

Extra light % Percent of kernels in extra light category (DFA)

Light % Percent of kernels in light category (DFA)

Light amber % Percent of kernels in light amber category (DFA)

Amber % Percent of kernels in amber category (DFA)

Tip shrivel % Percent of kernels with tip shrivel like ‘Chandler’

Veins % Percent of kernels with conspicuous veins

-   -   “DFA” refers to Dried Fruit Association of California 

What we claim is:
 1. A new and distinct cultivar of walnut tree designated ‘Solano’ as shown and described herein. 